Comments on: Lindzen’s PNAS Reviewshttp://climateaudit.org/2011/06/10/lindzens-pnas-reviews/
by Steve McIntyreTue, 31 Mar 2015 21:57:28 +0000hourly1http://wordpress.com/By: PNAS Reviews: Preferential Standards for Kemp (Mann) et al « Climate Audithttp://climateaudit.org/2011/06/10/lindzens-pnas-reviews/#comment-292770
Wed, 22 Jun 2011 18:50:37 +0000http://climateaudit.org/?p=13844#comment-292770[…] 10 days ago, we discussed the PNAS reviews of the recent submission by Richard Lindzen, a member of the National Academy of […]
]]>By: David Weismanhttp://climateaudit.org/2011/06/10/lindzens-pnas-reviews/#comment-289696
Fri, 17 Jun 2011 12:27:38 +0000http://climateaudit.org/?p=13844#comment-289696Usually when you extensively discuss a published or unpublished paper you examine the statistics supporting said paper carefully, even if that paper is not the whole subject of your post. I’ve never seen you discuss a paper by a member of the team, and compare it to other papers published in the same journal which did not involve climate science, although I’ve read about flawed statistics in other papers as well.
]]>By: Robhttp://climateaudit.org/2011/06/10/lindzens-pnas-reviews/#comment-289571
Fri, 17 Jun 2011 07:03:45 +0000http://climateaudit.org/?p=13844#comment-289571Regarding this new Lindzen and Choi 2011 paper, as far as I can see on the various blog, there is a great deal of talk about the PNAS rejection, but very very little about the science in the paper.

Lindzen and Choi obtain different feedback numbers from the same ERBE data than Trenberth 2010 and two other papers, and Lindzen claims (unsurprisingly) that his method is more accurately reproducing feedback numbers.
When I looked at the details of his method however, I found something very concerning :

The Lindzen and Choi method of doing FLUX/SST analysis (called “lead and lag” by Lindzen) seems to have a (strong?) bias towards negative feedback.
Here is why :
L&C analyzes fragments of SST changes that are either rising or falling, and then measures the FLUX response over the same period.
No problem there, has been done many times before by numerous other scientists.
The difference is that Lindzen is looking back and forth (lead and lag) in time, and finds the FLUX response that has the highest correlation with the SST change.

First remember that the FLUX (response) has significant noise on it. Let’s note that if you do not look back and forth in time (no lead or lag), then on average the FLUX response will tell you the average FLUX response to that SST change.
But also remember that the FLUX response with the highest correlation with SST will always be the response that starts at one extreme and ends at the other extreme. All other responses will correlate less, since they will show opposite slopes at the start and/or end points, which obviously don’t correlate well with the SST.
So, if you are allowed to look back and forth in time through that noisy signal, you have a high chance of finding a lead or lag time where the FLUX response is larger (and thus correlates better) than the no-lag response alone.
So Lindzen and Choi method will (for each fragment of SST analysed) find the lead or lag time where the FLUX response is the largest !

When the FLUX response is larger for a certain SST change, the calculated feedback will be lower, and thus this method has a bias towards lowering the feedback calculated from the ERBE data.
Let me note that the effect (bias) will be stronger the more lead or lag time is allowed, since there will be more start and end-points in the noise to consider, and the largest response will correlate the best.
So for short lag times and strong negative feedback (large FLUX response), Lindzen’s method will be approximately correct. But for no-feedback or positive feedback the lead-lag bias will be very significant.

In fact Lindzen mentions himself that his method works best for large negative feedbacks .
He also mentions that his method works less good for small feedbacks (and consequently) large lag times, which, as I showed above is consistent with increased bias.

Interestingly enough, he does not show what feedback parameter number he obtains for a system with no feedback or positive feedback, in which case the lead-lag-noise bias will be greatest.

Needless to say that maybe Lindzen drew some very premature conclusions when he discards other scientists’ work (Trenberth et al, Dessler et al) who do NOT use his (biased) lead-lag-correlate method.

I have read your other posts above and understand your position, there is no reason to restate it. I raised a different issue and would like to hear your response to that.

Again, PNAS’ stated grounds for rejecting Chou as a reviewer was bias. The basis for that decision, however, is inconsistent with the facts. Its stated grounds for rejecting Happer was that he lacked qualifications in the subject matter.

At the same time, however, PNAS recommended other reviewers with lesser qualification and/or a demonstrably higher degree of bias. How is this possible unless PNAS is determined, regardless of the quality of paper, to exclude a certain set of views? In other words, what neutral standard could conceivably apply which would result in a rejection of Chou and approval of Schmidt?

Please note, I am not interested in your opinion of Chou or Happer. I don’t believe anyone in the world (beyond your close friends and immediate family) is interested in your opinion of these men. I certainly don’t want to give you another opportunity to engage in yet another round of stupid insults.

]]>By: MikeNhttp://climateaudit.org/2011/06/10/lindzens-pnas-reviews/#comment-288659
Wed, 15 Jun 2011 17:21:02 +0000http://climateaudit.org/?p=13844#comment-288659>Well, it is on the same subject in the sense that both found that there was a low sensitivity.

So does PNAS require no coauthors at any point in the past if you wrote a paper that supports the idea of a high climate sensitivity?

You are moving the goalposts.

]]>By: Venterhttp://climateaudit.org/2011/06/10/lindzens-pnas-reviews/#comment-288354
Wed, 15 Jun 2011 04:00:44 +0000http://climateaudit.org/?p=13844#comment-288354Oh, got it. He’s got a day job at NASA GISS. That explains it. No wonder a first year undergrad adopts this tone to start dissing any skeptic scientist. True to standards. No interest in Mann. Steig, Schnieder et. al. and their rubbish and puffball reviews by pals. But interested enough to come here and post against Lindzen with a lot of ad homs and talking about ” garbage not being allowed to be published etc. ” . Yes, pull the other one and it’s got bells on it.

And ” selectively quoted ” e-mails? Which part of which e-mail was ” selecttively quoted “? if you can, please point out with facts. It’a a chalengse and I’m prepared to put up 100 bucks o it. Go ahead.

We are old enough and experienced enough to recognise and smell hyprocrisy from a mile, especially in climate science.

The problem is that everyone here has been indoctrinated into thinking that…

My problem is your repeated use of absolutes, and again, lack of substance. I don’t know that it’s the root problem, but it certainly seems to betray your thought process, and tends to cause me to “read by” you. Just my opinion, but you may want to consider how you can communicate more effectively.